Aquaponics is the land based production of fish in tanks combined with the recirculation of the water from the fish tanks through hydroponic systems to produce high value horticultural crops. The waste products from the fish are converted by a bio-filter into soluble nutrients which are absorbed by the plants, and allow "clean" water to be returned back to the fish. Thus it produces valuable fish protein with a minimal pollution of fresh water resources, while at the same time producing horticultural (usually vegetable) crops. The production of fertilizers is becoming increasingly expensive due to high prices of fossil fuels, and this may have long term implications for nutrient use in agriculture in the future, particularly in developing countries. Aquaponics uses waste products derived from animals and plants which are fed to the fish, and thus converted into valuable animal protein and fresh vegetables. With the world's fresh water resources limited, aquaponics would appear to have considerable potential for developing countries.
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